Online In-Context Distillation for Low-Resource Vision Language Models
Zhiqi Kang, Rahaf Aljundi, Vaggelis Dorovatas, Karteek Alahari
TL;DR
This work tackles the challenge of adapting vision-language models to low-resource settings by introducing Online In-Context Distillation (ICD), a training-free framework where a small student model inherits knowledge from a large teacher through inference-time demonstrations. ICD integrates test-time scaling to improve teacher annotations, a cross-modal demonstration selection mechanism to robustly curate demonstrations, and uncertainty-aware querying to limit teacher calls while ensuring informative context. The approach is analyzed to identify when ICL can benefit small VLMs (notably in the 4B–12B range) and demonstrates that training-free ICD can bridge much of the gap to larger teachers with modest compute and annotation budgets, achieving average gains around 14.8% across tasks and limited teacher annotation rates (~14.7%). Overall, ICD offers a practical, scalable path to deploy capable VLMs on edge devices by avoiding fine-tuning and heavy annotation while maintaining strong performance relative to zero-shot and, in some cases, the teacher’s zero-shot capabilities.
Abstract
As the field continues its push for ever more resources, this work turns the spotlight on a critical question: how can vision-language models (VLMs) be adapted to thrive in low-resource, budget-constrained settings? While large VLMs offer strong performance, they are impractical to deploy in such settings. Small VLMs, on the other hand, are efficient but typically require costly fine-tuning to close the performance gap with larger models in the deployment domain. Inspired by the in-context learning framework, we propose an online In-Context Distillation (ICD) method, in which a small VLM collaborates with a stronger teacher model at inference time, distilling its knowledge via sparse demonstrations to efficiently bridge the gap between them. Our method is built on an in-depth analysis that identifies the scale and the choice of models for which vision-language ICL is currently feasible, and demonstrates the advantage of ICL over fine-tuning under constrained compute budgets. We enhance our method with a novel cross-modal demonstration selection strategy, teacher test-time scaling to reduce noise, and student uncertainty conditioning to dynamically populate a demonstration pool and minimize teacher queries. Our ICD method significantly boosts the performance of small models (up to 33%) using scarce teacher annotations (as low as 4%), and competes with the teacher's zero-shot performance.
